The Lycaesaurus is an intelligent, dog-sized predator that hunts in the grasses. Mating for life, pairs dig burrows in the volcanic soil and line them with dry vegetation for their pups (most often twins). They take a wide range of prey, feeding on anything smaller than themselves, and often follow larger carnivores like V.Rexes (even at the risk of being bullied by the tyrannosaurs) in the hopes of scavenging morsels from their kills, or using the cover of one of their attacks to grab undefended young dinosaurs, such as that of Ferrucutus.
The cunning Lycaesaurus have developed tactics to lure Brutornis mothers off their valuable eggs. Conspicuously approaching the nest to catch the bird's eye, one Lycaesaurus will act as a decoy, luring the protective mother off her clutch while the other raids the unattended nest. A valuable protein source, the melon-sized eggs are worth the risk of teasing such a dangerous larger predator. The decoy individual has to judge its lead carefully. If it goes too far, the mother Brutornis might abandon pursuit to return to her eggs; too close and the ploy could turn to disaster, the would-be egg thieves becoming dinner for the starving parent bird.